Page 1 - Home Assignment-1 S A and V cuboids
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SAI International School
                                                     CLASS - IX

               Mathematics
               CHAPTER-13: SURFACE AREAS AND VOLUMES

               HOME ASSIGNMENT-1 [CUBOIDS AND CUBES]
               1.    The surface area of a cube whose edge equals to 3cm is:

                     a. 62            b. 30              c. 54                d. 90     
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               2.    If the length of the diagonal of a cube is 6√3 cm, find the edge of the cube and its
                     total surface area.
               3.     Find the length of the longest pole that can be put in a room of dimensions 10 m x
                     10 m x 5 m.

               4.     Manoj Sweets placed an order of making 30 cm x 20 cm x 6 cm cardboard boxes
                      for packing their sweets. For all overlaps, 5 % of total area is required extra. If cost
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                      of the cardboard is Rs 2 for 1000 cm , find the cost of the cardboard used for
                      making 500 boxes.

               5.    The total surface area of a cube is 726 cm . Find the length of its edge.
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               6.     Two cubes of edge 6 cm are joined to form a cuboid. Find the total surface area of

                      the cuboid.


               7.     The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four
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                      walls at the rate of 10 per m  is Rs. 15000, find the height of the hall.


               8.     A small indoor greenhouse (herbarium) is made entirely of glass panes (including
                      base) held together with tape. It is 30 cm long, 25 cm wide and 25 cm high.
                                 (i) What is the area of the glass?
                                 (ii) How much of tape is needed for all the 12 edges?


               9.       Rinku has built a cuboidal water tank in his house. The top of the water tank is
                     covered with an iron lid. He wants to cover the inner surface of the tank including the
                     base with tiles of size 10 cm by 8 cm. If the dimensions of the water tank are 180 cm
                     x 120 cm x 60 cm and cost of tiles is Rs. 480 per dozen, then find the total amount
                     required for tiles.
               10.  The length, breadth and height of a room are 5m, 4m and 3m respectively. Find the
                     cost of white washing the walls of the room and the ceiling at the rate of Rs. 7.50 per
                     m .
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